Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer
Due to their excellent capabilities to generate and sense ultrasound signals in an efficient and well-controlled way at the microscale, piezoelectric micromechanical ultrasonic transducers (PMUTs) are being widely used in specific systems, such as medical imaging, biometric identification, and acous...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-01-01
|
| Series: | Micromachines |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-666X/14/1/210 |
| _version_ | 1797438617028657152 |
|---|---|
| author | Tao Li Le Zhang Wenping Geng Jian He Yongkang Rao Jiabing Huo Kunxian Yan Xiujian Chou |
| author_facet | Tao Li Le Zhang Wenping Geng Jian He Yongkang Rao Jiabing Huo Kunxian Yan Xiujian Chou |
| author_sort | Tao Li |
| collection | DOAJ |
| description | Due to their excellent capabilities to generate and sense ultrasound signals in an efficient and well-controlled way at the microscale, piezoelectric micromechanical ultrasonic transducers (PMUTs) are being widely used in specific systems, such as medical imaging, biometric identification, and acoustic wireless communication systems. The ongoing demand for high-performance and adjustable PMUTs has inspired the idea of manipulating PMUTs by voltage. Here, PMUTs based on AlN thin films protected by a SiO<sub>2</sub> layer of 200 nm were fabricated using a standard MEMS process with a resonant frequency of 505.94 kHz, a −6 dB bandwidth (BW) of 6.59 kHz, and an electromechanical coupling coefficient of 0.97%. A modification of 4.08 kHz for the resonant frequency and a bandwidth enlargement of 60.2% could be obtained when a DC bias voltage of −30 to 30 V was applied, corresponding to a maximum resonant frequency sensitivity of 83 Hz/V, which was attributed to the stress on the surface of the piezoelectric film induced by the external DC bias. These findings provide the possibility of receiving ultrasonic signals within a wider frequency range, which will play an important role in underwater three-dimensional imaging and nondestructive testing. |
| first_indexed | 2024-03-09T11:40:37Z |
| format | Article |
| id | doaj.art-cdac3dbf26a34f05a2910e32aef7de2c |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T11:40:37Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-cdac3dbf26a34f05a2910e32aef7de2c2023-11-30T23:34:44ZengMDPI AGMicromachines2072-666X2023-01-0114121010.3390/mi14010210Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic TransducerTao Li0Le Zhang1Wenping Geng2Jian He3Yongkang Rao4Jiabing Huo5Kunxian Yan6Xiujian Chou7Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaScience and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, ChinaDue to their excellent capabilities to generate and sense ultrasound signals in an efficient and well-controlled way at the microscale, piezoelectric micromechanical ultrasonic transducers (PMUTs) are being widely used in specific systems, such as medical imaging, biometric identification, and acoustic wireless communication systems. The ongoing demand for high-performance and adjustable PMUTs has inspired the idea of manipulating PMUTs by voltage. Here, PMUTs based on AlN thin films protected by a SiO<sub>2</sub> layer of 200 nm were fabricated using a standard MEMS process with a resonant frequency of 505.94 kHz, a −6 dB bandwidth (BW) of 6.59 kHz, and an electromechanical coupling coefficient of 0.97%. A modification of 4.08 kHz for the resonant frequency and a bandwidth enlargement of 60.2% could be obtained when a DC bias voltage of −30 to 30 V was applied, corresponding to a maximum resonant frequency sensitivity of 83 Hz/V, which was attributed to the stress on the surface of the piezoelectric film induced by the external DC bias. These findings provide the possibility of receiving ultrasonic signals within a wider frequency range, which will play an important role in underwater three-dimensional imaging and nondestructive testing.https://www.mdpi.com/2072-666X/14/1/210piezoelectric micromachined ultrasonic transducer (PMUT)aluminum nitride (AlN)microelectromechanical system (MEMS) fabricationDC biasfrequency characteristics |
| spellingShingle | Tao Li Le Zhang Wenping Geng Jian He Yongkang Rao Jiabing Huo Kunxian Yan Xiujian Chou Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer Micromachines piezoelectric micromachined ultrasonic transducer (PMUT) aluminum nitride (AlN) microelectromechanical system (MEMS) fabrication DC bias frequency characteristics |
| title | Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer |
| title_full | Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer |
| title_fullStr | Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer |
| title_full_unstemmed | Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer |
| title_short | Fabrication and DC-Bias Manipulation Frequency Characteristics of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer |
| title_sort | fabrication and dc bias manipulation frequency characteristics of aln based piezoelectric micromachined ultrasonic transducer |
| topic | piezoelectric micromachined ultrasonic transducer (PMUT) aluminum nitride (AlN) microelectromechanical system (MEMS) fabrication DC bias frequency characteristics |
| url | https://www.mdpi.com/2072-666X/14/1/210 |
| work_keys_str_mv | AT taoli fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT lezhang fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT wenpinggeng fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT jianhe fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT yongkangrao fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT jiabinghuo fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT kunxianyan fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer AT xiujianchou fabricationanddcbiasmanipulationfrequencycharacteristicsofalnbasedpiezoelectricmicromachinedultrasonictransducer |